To fleer is to hold a loaded pipe (or other smoking device) for a long time while in a group of people smoking marijuana. This is often done at the annoyance of the other smokers who would like to take a hit.

Verb; Holding on to a marijuana pipe or other paraphernalia, usually while pausing for a story or simply forgetting to pass the pipe, when one is in a group of others smoking marijuana. This is usually said when expressing annoyance with the person who is not passing.